Spatiotemporal Evolution of Vegetation Coverage in Longnan City Based on NDVI Data
In order to study the vegetation cover change in Longnan City,based on the Normalized Difference Vegetation Index(NDVI)data from 2001 to 2020,this paper used the maximum composite Fractional Vegetation Cover(FVC)of the pixel dichotomous model,and systematically analyzed the spatiotemporal evolution character-istics of vegetation coverage in Longnan City,Gansu Province in the past 20 years by Sen trend analysis,Mann-Kendall significance test,Hurst index and other methods,and predicted its development trend.The results showed that:① The vegetation coverage in Longnan City showed a fluctuating upward trend as a whole,with a change rate ranging from(-0.0417208～0.0479985)/a;② There were significant differences in the stability of vegetation coverage in different regions,with 7.26％of the areas with stable vegetation coverage,31.12％of the areas with significant improvement,and 9.39％of the areas with severe degradation.③ In the evolution trend of vegetation cover,persistence and anti-persistence were staggered,and the overall pattern was weak persistence.The results of this study can provide a reference for the restoration and protection of the ecological environment in Longnan City.
Fractional Vegetation Cover(FVC)spatiotemporal evolutionTheil-Sen median trend analysisLong-nan City
NETL
NSTL
万方数据
